Geometry - lines, angles & relationships

20 terms

line segment

has definite starting & end points

point

used to name; usually a capital letter

ray

has a definite starting point & continues without end in the opposite direction

segment

part of a line with two endpoints

plane

a flat surface that extends forever.

transversal

extending or lying across

supplementary angles

Two angles whose sum is 180 degrees; one obtuse, one acute

complementary angles

Two angles whose sum is 90 degrees

vertex

A point where two or more straight lines meet.

perpendicular lines

Two lines that intersect to form right angles

parallel lines

lines that never intersect

line

extends without end in opposite directions

acute angle

an angle less than 90 degrees but more than 0 degrees

obtuse angle

An angle that measures more than 90 degrees but less than 180 degrees

straight angle

an angle that measures 180 degrees

right angle

an angle that measures 90 degrees

vertical angles

a pair of opposite congruent (=) angles formed by intersecting lines